"Space roo" helps climate change experiment

A 100-foot tall kangaroo made of white cardboard is laid out on a paddock at Monash University in Melbourne. Scientists in Australia hope the white kangaroo, photographed from space on Tuesday, will help them better understand how the earth reflects sunlight and give them new clues about global warming.

Measuring the changes in the climate requires all kinds of specialized equipment, such as advanced computer models, orbital radars, seafaring robots, and giant cardboard kangaroos.

The last one, a 100-foot by 60-foot white image of Down Under's iconic marsupial laid out on the campus of Monash University in Melbourne, is being used to measure the earth's albedo, that is, its ability to reflect heat back into space. On Tuesday morning, four NASA satellites that regularly pass over Australia photographed the cutout as it reflected sunlight back into space. The images will be compared with similar images a year earlier to help measure the contribution of the earth's albedo to climate change.

The Age, an Australian daily, quotes Graeme Pearman, one of Australia's leading climate scientists, who explains that, while white surfaces reflect heat into space, darker areas absorb heat, warming the planet.

Albedo can have a disastrous effect on the planet. Dr Pearman said last year's Intergovernmental Panel on Climate Change Report estimated that the polar ice caps, which help keep the polar areas cool, could disappear in the summer months by 2050.But, Dr Pearman said, there was a 20% ice cap reduction last year alone, so the albedo effect — where melted ice creates more dark water surfaces that absorb more heat which then melts more ice — might mean the ice caps disappear much more quickly than estimated, quickening the pace of climate change.

These positive feedback loops make predicting changes in the climate a complex task. One possibility, reports the Age, would be that the earth becomes covered in a thick, white cloud, a scenario that would actually cool the planet.

The "space roo" as the cardboard macropod is known, drew a number of students and others interested in learning about climate change, or to simply pose for an orbital photo. Everyone who wanted to be in the pictures was asked to wear a white shirt, to maintain the image's albedo.